Digital or analog signal transmissions are used in virtually every aspect of modern society—in both wireless and wired applications. For example, cell phone usage is rapidly increasing around the world. Developing countries are finding it less expensive to invest in cellular phone systems than to install the copper wire or fiber optic infrastructure that more developed countries have used. Easy-to-use wireless networks have enabled increased laptop and smart phone usage at speeds only once achieved over wired networks. Traditional wired networks, which were conventionally adapted for powerful desktop or workstation computer systems, are now supporting myriad portable devices and an ever expanding Internet.
Advances in computer and storage devices have also pushed processing and transmission speeds to previously unexpected levels. Systems employing high-speed serial data communication protocols are becoming prolific. For example, storage devices are commonly using high-speed and low cost interfaces such as the Serial Advanced Technology Attachment (SATA) storage protocol. High-speed communication busses are also incorporating improved technologies such as Peripheral Component Interconnect (PCI) motherboard-level interconnection protocols (e.g., PCI Express®), among others, and have provoked new high-speed computing devices into the marketplace at steadily lower price points. Moreover, in a post 911 world, usage of wireless communication, security requirements, and low power circuit design is spreading widely.
Because of the high-bandwidth and multiple use nature of these signals, the transmission of digital or analog signals can be bursty. For example, many types of Radio Frequency (RF), radar, and high speed digital transmitters do not operate continuously, but rather, they often transmit a burst of information for a period of time, followed by a gap having little or no information. However, conventional test and measurement devices are deficient in the area of isolating and analyzing bursts and/or gaps between bursts of specific length, or otherwise detecting and measuring other aspects of high-frequency signals. As a result of random burst lengths, and in some cases, in the presence of a very high-frequency carrier signal—existing methods of triggering, such as edge trigger, cannot isolate specific bursts. Therefore, it is difficult or impossible to diagnose problems in the signal transmissions or to identify time intervals of interest.